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FERTILIZERS: 



THEIR 



Source, Purchase #Use 



BY 



CARROLL B. SMITH 




SECOND EDITION 




COPYRIGHT DEPOSIT. 




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FLRT1L1ZLR5: 



Their- 



Source, Purchase, and Use 

"Written for the Use of Farmers 
and Fruit Growers, With Special 
Reference to Citrus Culture. :: :: 
By 

CARROLL B. 5MITH 




SECOND LDITION 

Revised and Lnlarged 



REDLANDS. CALIFORNIA: 
CITROGRAPH BOOK PRESS 

19 11 



■ A' 



COPYRIGHXED 1911 

BY 
CARROLL B. SMITH 



^C!.A305846 



"'0!V 



TO THE READER. 

This work is designed expressly for those 
who are forced to use fertilizers and yet have 
not the time to investigate the subject as they 
would like to. It is intended to be brief and 
suggestive of thought to the reader rather 
than complete and final. 

Technicalities are avoided and illustrations 
simplified as much as possible. 

All the facts and deductions contained are 
based on the highest authorities on the sub- 
jects mentioned, and largely on the results of 
actual experience in California. 

The author hopes that the matter here given 
will aid the farmer to choose and purchase his 
fertilizers most wisely, and help him to get the 
best possible results from their use. There is 
no final authority in Nature. Every farmer's 
problems are his own and he must do his own 
thinking. The author has tried to present 
only the well established facts and general 
PRINCIPLES. A fuller knowledge of these, 
properly applied, will lead to better results 
and larger profits. 

CARROLL B. SMITH. 
Redlands, California. 



Note : This book has cross references throughout ; 
that is, when a number in parenthesis follows a 
sentence or paragraph it refers to some other para- 
graph or sentence having the same number, and 
treating of the same subject. Any phase of the 
Fertilizer question can thus be followed throughout 
the book. 



FERTILIZERS: 

Their Source, Purchase and Use 



SOMETHING ABOUT PLANTS. 

CIRCULATION. 

1. The higher plants (Fruit and Forest trees) have 
a well defined circulatory system. Beginning with 
the absorption by the root , hairs of soil moisture, 
containing dissolved plant food, one set of tissue 
termed xylem carries this moisture or sap upward 
into the leaves and is there lost. In the leaf 
the sap is transformed or elaborated largelj^ by sun- 
light, according to the plant's nature and needs, and 
returned to the branches and trunk of the tree and 
its fruit, by another distinct set of tissue termed 
phloem. Both these sets of tissue are, roughly 
speaking, found in the ''Cambium" or sap layer of 
the bark. They are between the real bark and the 
wood of the tree. Wood is built up on one side and 
bark on the other. In a cross section of a limb or 
trunk of a tree these different tissues might be illus- 
trated, as in Fig. 1. 

The life of the tree is in the cambium. When we 
bud or graft it is cambium layer contact we want in 
both stock and scion. If the cambium is severed 
completely around the tree it dies. All of the soil 
derived plant foods enter the tree through its xylem 
tissue, found in the cambium layer. 



FERTILIZERS 



RESPIRATION. 



2. Plants have a respiratory system. They ab- 
sorb oxj^gen and give off carbonic acid, mostly at 
night, but during the day more oxygen is given off 
and carbonic acid absorbed. The leaves and some of 
the green bark are the respiratory system. Carbon 
and oxygen thus enter the plant directly from the air 
as well as by water from the roots. 



Oii-tir £<^rl{ 







BA\KS 



oocL 



oLcL 



TitL 



FIGURE 1 
TRANSPIRATION. 

3. Plants give off water (Transpiration) at all 
times of day and night. The water escapes at cer- 
tain pores, called Stomata, of the leaf contained also 
in very young bark. Water carries the plant food 
into the plant by way of the roots. The plant foods, 
changed and elaborated, are retained in the tissue as 
new growth while the water passes off through 
the leaves as a vapor. When transpiration exceeds 
the supply from the roots the plant wilts. If the air 
is saturated with moisture, plants give off less, but 



FERTILIZERS 7 

on hot days give off more. The leaves of fruit trees 
may be made large or small by an adequate or inad- 
equate supply of moisture. i';jThe^larger and healthier 
the leaves, the^more plant foodis^elaboratedj^and the 
better the growth and the crop. So the transpira- 
tion system and its healthy activities are very 
directly connected with the production of fruit. 

4. Any serious or prolonged check to the process 
of transpiration necessitates a long time for full 
recovery, frequently several years. A severe wilting 
will show for a year, but a slight wilting usually 
fully recovers after watering. Thus the importance 
of a regular and sufficient supply of water is evident. 

Water is the common carrier of all the plant's food, 
whether the food is derived from the air or from the 
soil (13), the only positively known exceptions being 
the absorption of carbon and oxygen by respiration. 

The whole movement of water from the root hairs 
to the leaf and back to other parts of the plant and 
fruit, is confined to the cambium layer in which are 
contained the xylem (upward flow) and phloem 
(downward flow) tissue. 

LEAVES. 

5. A good leaf is essential to the best results. 
Leaves put the plant in communication with sun- 
light, under which influence sap is changed and many 
products, incident and essential to growth, are 
manufactured. It is believed that all of the plant 
food brought into the tree by water, undergoes 
some change in the leaf (digestion) before it is finally 
added to the various tissue of the plant. If the leaf 
has been stunted or impaired by drought, frost or 
fire, it manufactures less of the products essential 



8 FERTIUZERS 

to growth. Less water can come into it ; therefore, 
less water and less food enter the plant. Less sun- 
light can act on it, and all of the activities of the 
plant are so reduced that the result is a small crop 
of undersized fruit. Consequently, a good leaf is 
essential to the best results. 

BARK. 

6. What has been said of the function of leaves is 
true, to some extent, of green bark. Old, corky bark 
may be regarded as the armor or shield to the cam- 
bium layer. But young, tender bark can carry on 
the process of respiration of carbon and oxygen, and 
of transpiration of moisture, and to that extent the 
transformation of the sap and plant food. Although 
these activities in bark are very limited, they are 
sufficient to continue the life of the tree should it 
ever become defoliated for purposes of transplanting 
or on account of disease or frost. Under the young 
bark's continued activity new leaves may start, 
until finally the plant renews its full health and 
vigor. 

ROOTS. 

7. The distribution of plant food throughout the 
soil influences directly, and, with water, the entire 
development of the root. The absorptive power of 
the root is in the young, tender rootlets or fibres, 
by means of root hairs invisible to the eye. These 
root hairs are distributed along the length of the 
tender, growing fibre. The end of the fibre has a cap 
which protects it as it develops and crowds its way 
between the smallest soil particles. The very tips of 
roots and fibres cannot absorb moisture or food. 



FERTILIZERS 9 

FIBROUS ROOTS. 

8. If the soil is poor, the roots are very long and 
develop very few fibres and root hairs. But in a 
rich soil they are short and well branched, often 
forming a perfect mat of fibres. Under such fertile 
conditions the root hairs are more numerous and the 
plant's contact with the soil and its feeding powers 
are much greater. Consequently, roots develop 
where the food is. Fertilizers should be applied as 
deep as possible, so that root development w411 not 
be encouraged near the surface. (63) (79). 

SHALLOW WORK. 

9. If the application of fertilizers and water is 
limited to the top foot the most of the fibres are de- 
veloped there, and deep ploughing and cultivation 
become questionable policy. Thick water conserv- 
ing mulch becomes impossible, (see frontispiece). 
This is the actual condition where impervious strata 
or ''hard pan" lies near the surface. 

DEEP WORK. 

10. In open, deep soils where water can go down 
easily, the plant food is more widely distributed and 
likewise the fibrous roots. Here, deep work and a 
deep mulch are possible, and in case of water short- 
age, would be found a great advantage, as there is a 
better reserve supply in the sub-soil. 

APPLY FERTILIZER DEEPLY. 

11. Present practice applies all fertilizer between 
the surface and the bottom of the plow furrow. 
This is unavoidable, even in open soils where the 
water is easily absorbed. Methods of effecting 



10 FERTILIZERS 

deeper applications without serious root disturbance 
are unknown. As a result roots are encouraged 
near the surface, and this fact is the best argument 
advanced for the use of the most water soluble forms 
of fertilizer obtainable, as they are more widely dis- 
tributed by the movement of water. (77) (79). 

SOILS AND ROOTS. 

12. The permeable character of the soil influences 
the root development, aside from the question of 
plant food. In clay or adcbe soils there is a limited 
root development and a resultant smaller tree. 
" Hard pans " near the surface have the same limit- 
ing influence. In such soils, more trees can be 
planted to the acre. 

Open, free loams or gravelly, sandy loams permit 
a larger root development and trees should be 
placed further apart. These are usually local ques- 
tions, but should be considered by the intending 
planter. The mechanical or physical nature of the 
soil should be known to a considerable depth. (20- 
22). 



FERTILIZERS 



11 



SOMETHING ABOUT SOILS. 

13. Of more th^ln seventy elements known to 
chemistry, fourteen have been found to be essential 
to plant life, Ten of these are soil derived, and four 
are derived from the air : 



Air Derived. 
Carbon 
Oxygen 
Hydrogen 
Nitrogen 



Soil Derived. 
Calcium 
Silicon 
Iron 

Magnesium 
Manganese 
Sulphur ^ 

Chlorine 
Sodium 
Potassium 
Phosphorus 
These fourteen elements, in var^dng portions, are 

peculiar to all plants so far as different species have 

been examined. 
14. All soils, for convenience, may be considered 

as composed of various portions of: 

. Sand 



Rock Powder / 
Silt \ 

Clay 

Humus / 

Plant food \ 



> or simply ^ Clay 



Humus 



Sand is rock powder and may or may not contain 
silt. Clay is a chemical compound and a very im- 
portant element of soils, as it retains large amounts 
of moisture. If too abundant, the soil is intractable 



12 FERTILIZERS 

and hard to manage, and bakes easily and while 
sand alone is too porous to retain moisture, the 
addition of a little clay with sand makes the proper 
balance for retaining moisture and for friabilit3^ 

15. Humus, decayed organic matter, is absolutely 
essential as it is the source of the necessary nitrogen. 
It is a fundamental truth in connection with this sub- 
ject that there is no fertility without humus. It also 
influences favorably, as nothing else will, the soil's 
mechanical condition and moisture content, besides 
supplying essential plant foods. 

The humus which plants contribute to the soil 
not only furnishes all of the soil nitrogen, except 
that artificially added, but gives life to numerous 
forms of bacterial life, with which every healthy soil 
is teeming. We cannot discuss this subject here (86- 
89), but it will suffice to say that, without the 
contribution made by plants to the soil, the micro- 
scopic forms of life could not exist and they are now 
regarded as essential to fertihty. Indeed, it is pos- 
sible to inoculate soils with beneficial bacteria, and 
improve their fertility. 

A soil may contain sand, clay and humus and yet 
lack some essential plantfood, hence the last division. 
But as a rule, sand, clay and humus in proper pro- 
portions will, for a time at least, supply all the 
requirements of plant life. 

The plant requires of the soil that it furnish the 
ten named soil derived elements, and the soil requires 
of the plant that it supply humus and such of the 
air derived elements as are necessary to its own 
health and fertility. Just what amounts of hydro- 
gen, oxygen, carbon and nitrogen are absorbed 



FERTILIZERS 1 3 

directly from the air, and how much is contributed 
by plant life, is not known. But it is generally be- 
lieved that most of these elements as found in soils 
are derived from plants, either through the agency 
of beneficial bacteria or from the decay of vegetable 
tissue. 

16. The character of vegetation changes with the 
soil. Pure clay soils support very little plant life, as 
there is no drainage, no ventilation and no 3aelding 
to root penetration. The right degree of porosity, 
due to the presence of sand and humus, allows the 
roots to enlarge rapidly which in turn nourishes a 
large plant. Hence the same species of plants v^ill 
vary in size and appearance according as the nature 
of the soil encourages or restricts their growth. A 
well developed root means a well developed plant 
and vice versa. 

If potassium or sodium or chlorine are in excess, 
the soil is alkaline and tolerated by certain classes of 
plants like the salt bushes, some of the mallows^ 
tussock grass, etc. 

Peat lands, bogs and meadows have a characteris- 
tic vegetation. Peat may contain as high as 80 j^^ 
humus or decayed organic matter. Here, nitrogen 
is naturally in excess and moisture plenty, so that 
the growth is vigorous and succulent. Tall grasses, 
and willows thrive here. 

The v^^ell drained ''mesa" of the arid west, sup- 
ports another variety of vegetation and a dense 
forest cover or leaf mould, still another, according to 
their moisture holding powers. The various com- 
binations of sand, clay, humus and plant food are 
almost infinite. 



14 FERTILIZERS 

17. Soils vary in chemical composition according 
to depth. The surface foot or two feet usually con- 
tains the bulk of the nitrogen, due to the fact that 
the nitrates are water soluble and the evaporation 
of moisture at the surface leaves the nitrates and all 
soluble plant foods there for the benefit of young 
plants whose roots have not gone deep. Young 
plants must grow first, and nitrogen produces 
growth. As the plant matures, its roots penetrate 
lower into the region where the nitrogen is scarce 
and where the phosphates, silicon, lime and insoluble 
elements are more evenly distributed. There, fruit 
production and maturing of tissue take place. 

During the time growth is vigorous, fruit produc- 
tion is limited or impossible even in the case of 
mature trees when artificialh^ forced to an abnor- 
mally vigorous growth. 

18. While nitrogen is the chief element of grow^th, 
other elements of the soil favor fruit production. 
Phosphorus is definitely known to be one of these. 
(70). If the fruit producing elements of the soil w^ere 
abundant on the surface, and nitrogen, relatively 
deficient there, then fruit trees w^ould be heavily 
laden before they were taken from the nursery. 
There is abundant evidence of order and design in the 
methods of nature. "First the blade, then the ear, 
then the full corn on the ear," and the soil is so 
arranged as to effect the order. 

19. It is interesting to note briefly that the func- 
tion of potassium is to mature the growth that 
nitrogen produces. Where nitrogen is in excess of 
potassium, as in bogs and peat lands, the growth is 
soft and watery, whereas if potash is abundant and 



FERTILIZERS 1 5 

the nitrogen supply less, the growth is hard and 
firm. As illustration : note the strength of chap- 
arral wood, compared with marsh land growth. 
Nitrogen is deficient (comparatively) where the chap- 
arral grows and the mineral or soil derived elements, 
including potassium, relatively abundant. In a 
word, potassium gives starch or stiffness to the 
plant. Young peppers, acacias and eucalyptus trees 
bend frequently to the ground because their roots are 
in the surface soil, feeding on the excess of nitrogen 
and water. Older trees with deeper roots have not 
this tendency. (71). 

Sulphur, iron, calcium and silicon also perform 
special parts in the building of plant tissue, but a 
discussion of these would extend our subject unneces- 
sarily; ThcA^ are not "essential" plant foods. (23). 

PHYSICAL CONDITIONS. 

20. In California the mechanical or physical con- 
dition of the soil is of greater importance than the 
chemical composition. Especially is this true of cit- 
rus culture, where irrigation and cultivation are so 
frequent and thorough. The first sign of trouble is 
usually a slight j^ellow color of the foliage and is 
usually traceable to loss of humus and its conse- 
quent nitrogen. Yet the cause may be due to the 
roots entering a "hard pan" or coarse gravelly 
strata, less favorable to growth. (99). In any 
event the soil's mechanical condition should be 
known to a depth of at least five feet, and deeper if 
possible. The loss of humus so changes the soil's 
condition that the trees cannot derive the benefit of 
the water, the cultivation or the labor gives to it, 
and the first sign is the loss of the healthy green color. 



16 FERTILIZERS 

Applications of nitrate are helpful but not lasting 
unless applied in organic forms, capable of making 
humus. (86) (96). 

DRAINAGE. 

21. Citrus soils must be well drained. The top 
soil may be free from gravel for a considerable depth 
as long as it does not hold free water. The "mesa" 
or ''bench" soils of California, usually situated 
near the foot hills, are ideal in this regard. Figure 2 
is a photograph of a stream bank, running through 
a "mesa." The top soil, free from rock, is here 
about 5 feet deep, below which there is excellent 
drainage. 

HARD PANS. 

22. Occasionally the best situation and soil for 
fruit culture is underlaid at a few feet with an im- 
pervious strata, so that orchards soon show lack of 
vigor. These "hard pans" may be at the very sur- 
face or at any depth below. Blasting with powder 
or dynamite to break up the fixed condition is effec- 
tive, but must be repeated from time to time. Per- 
haps the best remed3^ where water is sufficient, is to 
prepare it long before planting trees, by raising a 
one or two year old stand of alfalfa, the roots of 
which penetrate hard soils to a considerable depth. 
Though the orchard is already established, alfalfa 
might be grown in alternate spaces between the 
tree rows for two years, then ploughed under and 
the remaining spaces planted for the next two years. 

"Hard pans" are usually deficient in nitrogen, but 
may be well supplied with the other plant foods, 
and especially with lime and iron. The latter gives a 
very noticeable deep red tint to the orange. 




FIGURE 2 



FERTILIZERS 1 7 

ESSENTIAL PLANT FOOD. 

23. Each of the three plant foods, nitrogen, phos- 
phoric acid and potash, are called essential ingredi- 
ents in fertilizers, as the3' are the elements first 
exhausted from the soil by plants. There are eleven 
other elements just as essential to perfect plant 
growth as these three, but the soil never becomes 
depleted of them, and it is not necessary to supply 
them, except in rare cases. Sometimes lime is sup- 
plied to the soil, though not regularly, to set free 
nitrogen, phosphoric acid and potash, when they 
are known to be in the soil in insoluble condition 
and large amounts. But, as lime adds no necessary 
ingredient, its continued use alone wall exhaust a 
soil. If a soil is known to lack iron, this may be 
added to make green foliage and to deepen the color 
of oranges. 

If a soil becomes unproductive under conditions of 
good tillage and water, it is usually because one or 
more of the essential plant foods has become ex- 
hausted. Hence commercial fertilizers have come to 
be composed of various amounts and forms of nitro- 
gen, phosphoric acid and potash. Commercial fer- 
tilizers are simply concentrated forms of plant food. 
A good top soil contains every element essential to 
plant growth and is a fertilizer, but it is not suffi- 
ciently concentrated to pay for handling and trans- 
portation. 

24. Each of the three plant foods, nitrogen, phos- 
phoric acid and potash, have their respective market 
values for each 1 per cent., or unit, of 20 pounds to 
the ton. If a ton of fertilizer contains 3 per cent, of 
an element that means 60 pounds. The purchaser 



18 FERTILIZERS 

will have to know in addition to the amount, the 
market value and the source of the nitrogen, phos- 
phoric acid and potash, before he can determine the 
value of a ton of certain analysis. The source is 
very important, because the most available forms 
have the highest market value. Without this know- 
ledge, a certain brand may sell for $40 a ton and 
another worth onlj- one-half its value ($20 per ton) 
may sell more readily for $38. 

25. Each of the three essential plant foods has 
its special part to do in the building of the plant. 
One cannot do the work of the other. As an illus- 
tration: Nitrogen in the absence of potash may 
produce a luxuriant and rapid growth but it will 
be weak, and broken dov/n by the first wind ; add 
potash and that same succulent, weak growth will 
be matured and have strength enough to carry its 
load of fruit. Potash alone will not produce the 
growth, but will mature it. Both nitrogen and 
potash have manv other functions to perform. (69), 
(71). 

Phosphoric acid, or phosphorus, must be present 
in order that the plant may assimilate its nitrogen. 
The process (osmosis) by which nutrients pass 
through the plant from cell to cell is facilitated by 
the presence of phosphoric acid. Phosphorus is nec- 
essary for the seed's embryo development and for the 
formation of chlorophyl (the green coloring matter 
of plants). (70). 

Thus, while the essential plant foods each have 
many independent functions to perform, they are 
mutually dependent upon each other, and mutually 
helpful in the building of the plant tissue = 



FERTILIZERS 19 

The condition in the soil may be such that the 
purchase of only one fertilizing element is necessary, 
and since the source of nitrogen and phosphoric acid 
and their functions are so many and varied, the 
question, ''What fertilizer to use," and **Howto 
purchase it most economically," is of vital interest to 
the farmer and one difficult to solve. 



SOURCE OF FERTILIZERS. 

THE SOURCE OF NITROGEN. 

26. Nitrogen may be obtained from these sources : 
Air, ammonia, nitrates, and animal matter. In certain 
forms of minimal matter, such as hoofs, horns, coarse 
bone, leather and wool waste, the nitrogen becomes 
available too slowly to be of much value. But as 
green manure, ammonia, nitrates, blood, fine bone, 
tankage, or blood and bone, fish and finely ground 
and screened guano, the nitrogen is in good form 
and soon becomes available. 

27. As these forms require different lengths of 
time to become available, judgment must be used in 
their application. Nitrate of soda and sulphate of 
ammonia dissolve almost immediately in water, so 
the full amount of a year's supply should not be 
applied at once, as some will be sure to be lost in 
waste water. Blood and bone, as a source of nitro- 
gen and phosphoric acid, would be a better combi- 
nation than nitrate and bone. Blood and fish re- 
quire more time to become available than nitrates, 
and bone, a longer time than blood. (43) 



20 



FERTILIZERS 



The most valuable sources of organic nitrogen, 
from the standpoints of uniformity in composition, 
richness in the constituent, and availability, are dried 
blood, dried meat, and concentrated tankage, fish 
and animal, which are produced in large quantities 
in slaughter houses and fish canneries. 

28. The most concentrated form of nitrogen is 
ammonium sulphate, containing about 19X or 24^% 
of ammonia. Nitrate of soda contains as high as 
16% nitrogen, blood 14^^, hoof and horn meal, 14%, 
slaughter house tankage from 5% to 10%, raw bone 
'SV2%, bat guano S% to 20%, sea fowl guano 12%. 
There are numerous other sources of nitrogen, but the 
above are those most generally used. The contents 
as given are in terms of nitrogen and approximately 
the maximum. 









TtrfrU 




tcomJ}<ALtion 









FIGURE 3— THE NITROGEN CYCLE 



FERTILIZERS 21 

NITRIFICATION. 

29. This is the process by which the nitrogen of 
organic matter is changed into nitrates. The 
ammonia and nitrogen of all fertilizers comes from 
organic matter, and all organic materials contain 
more or less of those substances in some form. 
Nitrate of soda in the nitrified product of some 
organic material, whether of seaweed or animals, is 
not definitely known. Ammonium sulphate also 
has an organic origin, being a by-product of carbon- 
izing works. 

Humus (which is decayed animal or vegetable 
matter) is the main source of the plant's nitrogen. 
When organic matter is applied to the soil it must 
first decay and then nitrify before its nitrogen be- 
comes available to the plant. These two processes 
are necessary. The decay is produced by one set of 
bacteria and their product is humus. Then the sub- 
stance is attacked by another set of bacteria which 
form nitrates. This latter process is nitrification. 
The nitrates thus formed are water-soluble and can 
be absorbed b}^ root hairs into plant tissue. (See 
Figure 3.) 

NITROGEN FROM AIR. 

30. Certain plants of the leguminoScC group have 
power to accumulate nitrogen from the air in the 
process of growth. Such plants are the lupins and 
vetches, which with peas, clover, alfalfa and others, 
when grown as catch or cover crops and ploughed 
under, add to the store of nitrogen in soils. But in 
this case, as with other organic substances, the two 
processes of decay of tissue and nitrification, are nec- 
essary before the nitrogen thus gathered becomes 



22 FERTILIZERS 

available. As nitrogen is the most expensive of all 
fertilizing elements, the importance and economy of 
a green cover crop ploughed under is considerable. 

NITROGEN FROM BLOOD AND TANKAGE, GUANO, ETC. 

31. The nitrogen from organic sources such as 
blood, tankage, guano, is prompt and decided in its 
action under ordinary growing conditions if the 
materials are finely ground. If drilled or ploughed 
under with the soil reasonably moist and warm, the 
effect, of added growth or better color may be seen 
in 30 days. The finer particles decay and become 
available first, the coarser particles taking more 
time. The plant thus has a steady, long feeding 
period. Where fruit trees are grown during a long 
growing period as in arid countries, the organic 
forms of nitrogenous fertilizer are most satisfactory. 

NITROGEN FROM NITRATE OF SODA. 

32. This is an immediately available form of nit- 
rogen. It dissolves easily in water and can thus be 
carried down to the subsoil and leached away ac- 
cording to the course the water takes. It is there- 
fore, not so steady or long timed a feed for plants if 
it is all applied at one time. It is better, therefore, 
to make at least two applications during the grow- 
ing period. One objection to its continued use, as 
shown by Dr. King, is that in time the accumulation 
of the soda will combine with the soil carbonates 
and form carbonate of soda (black alklai) which in 
certain quantities is deleterious to all forms of vege- 
tation. Such a harmful accumulation may require 
years but it will finally become positive. Neither 
rains or irrigation will leach the soda away, if, as it 
is claimed, all the rains of England have not leached 
it away from the soils of Rothampstead Station. 



FERTILIZERS 23 

SOURCES OF PHOSPHORIC ACID. 

33. Phosphoric acid, or phosphorus, in fertil- 
izers, is always found in combination with other 
elements. Usually it is obtained from bone or phos- 
phate rocks. As rock it cannot become readily 
available without treatment with sulphuric acid. 
As bone, unacidulated, it must be very finely ground 
to be available, and when thus ground is undoubt- 
edly the best form for citrus culture, as it is all 
equally available and its ability to rot or ferment 
has not been destroyed by the acid. (40) 

ACIDULATED PHOSPHATES. 

34. These are made by treating bone or phos- 
phate rock with sulphuric acid. Their value may 
vary according to the amount of acid used by the 
manufacturer, and the phosphorus content of the 
mother rock. If 800 pounds of acid were used with 
1200 pounds of bone or rock, it would be a 40^o 
acidulation, as 800 is 40^ of 2000. 

In acidulated goods whether rock or bone, there 
are always three forms of phosphoric acid— a soluble 
form, a "reverted" form, and an insoluble form. The 
last is of least ''commercial" value, but may have 
very great agricultural value under proper soil con- 
ditions. The ''reverted" is of doubtful value, as it 
has to first undergo a chemical change before becom- 
ing available. An insoluble portion is necessary in 
order to obtain the soluble, but does not add value 
to the fertilizer. State laws allow the reverted to 
be estimated as available with the water soluble, so 
that the soluble and reverted forms constitute the 
commercial or "available" phosphoric value of a fer- 



24 



FERTILIZERS 



tilizer but not necessarily the agricultural value. 
(67). 

Most authorities claim as great a value for the 
insoluble form, in finely ground materials, provided 
there is a normal or plentiful supply of humus in the 
soil. (40). 

REVERSION. 

35. It must be remembered that in using acidu- 
lated goods (bone or rocks) if an abundance of lime 
be present in the soil, the soluble form of phosphoric 
acid unites chemically with the lime and is made 
again insoluble as if it had never been treated. Iron 
and alumina, and other bases, produce the same 
effect on acidulated phosphates. The reversion, how- 
ever, depends on the amount of acid used by the 
manufacturer and the quantity of lime, iron, etc., in 
the soil. (77). 

''fixing" power of soils. 

36. The following table will show the "fixing" 
power of a lime soil : 

PHOSPHORIC ACID "FIXED" BY SOIL. 



Kind of Soil. 


Grains. 


Grains of Soluble 
Phosphoric Acid 
Used. 


Phosphoric Acid 
retained by the 
Soil. 


Deep Red\ 
Loam j 


5250 


40.67 


After 

24 hours 


Grains. 

24.29 






8 days 


31.49 








26 days 


38.23 


Lime soil 


10500 


81.17 


24 hours 

8 days 

26 days 


72.81 
80.31 
81.17 



Even a rich peat soil, high in either lime or iron, 
will "fix" or hold phosphoric acid in an insoluble 
condition, as shown in 49. 



FERTILIZERS 25 



STEAMED BONE. 



37. Steaming bones removes the fat and gela- 
tines, thus facilitating decay and availability, as 
such bone can be ground finer than raw bone, and 
thus becomes more subject to the attack of soil 
moisture and various dissolving agents. 

Raw bone contains from 3% to 4^2% nitrogen and 
about 22% or 23X phosphoric acid. Steaming re- 
duces the nitrogen and correspondingly increases 
the phosphoric acid, so that steamed bone may run 
as low as 1% nitrogen and as high as 25% or 30% 
phosphoric acid. The best effect from the phos- 
phoric acid of steamed bone is had when the bone is 
used in connection with some ammoniate such as 
blood, tankage or manure. Nitrogen increases the 
efficiency of phosphoric acid, and for this reason 
phosphoric acid from animal or vegetable sources is 
regarded as the best, the most effective and the most 
readily available form. If mineral phOvSphates are 
used, there must be humus in the soil. (40.) 

THOMAS PHOSPHATE SLAG (POWDER). 

38. Thomas slag, a product from iron furnaces, 
is a good source of phosphoric acid, though not so 
generally used as bone or rock. This material has 
to be finely ground to be of value, as it is not acidu- 
lated. It will analyze as high as 20% phosphoric 
acid, usually 17%. Thomas slag also contains much 
lime, which fact should be considered when it is 
used in the presence of ammonium sulphate, or 
barn manures, as the lime will drive off the am- 
monia. An average analysis might show 17.28% 
phosphoric acid, 46.20% lime and iron oxide 18.37%. 



26 FERTILIZERS 

It may be used to best advantage on trees which 
have made strong, nitrogenous growth at the ex- 
pense of fruit production, and also on peaty soils, 
poor in lime. Water will not dissolve slag, there- 
fore it should be put in as deeply as possible. 

PHOSPHATE GUANOS. 

39. The guanos of bats and sea fowl are also 
valuable sources of phosphoric acid. These materi- 
als, however, vary in analysis very much. Each 
consignment should be analyzed and its price based 
on its contents. The first shipments from a guano 
deposit are usually the richest and most valuable, 
and may deteriorate as the deposit is drawn upon. 

CHEAPEST FORM OF PHOSPHORIC ACID. 

40. The Pennsylvania State Department of Agri- 
culture, in Bulletin No. 94, gives the results of 12 
years' experiments with phosphates, both acidu- 
lated and unacidulated, and seems to show conclus- 
ively that the best form in which to purchase phos- 
phoric acid is the untreated bone or rock. This is 
only on condition that there is plent3^ of organic 
matter, or humus-forming material, in the soil. 

Under such conditions (with humus in the soil) finely 
ground rock (unacidulated) gave better results than 
acidulated rock or bone. This was from the stand- 
point of both original cost of material and the 
results obtained, and was true of all crops tried, 
except wheat. Unacidulated fertilizers always con- 
tain more phosphoric acid than the same fertilizers 
acidulated, as the weight of the acid used displaces 
some of the material, and if organic matter is used 
with the former, the conditions thus created in the 
soil give it additional life which takes the place of 



FERTILIZERS 27 

acidulation, and results in greater fertility. A num- 
ber of lay experiments and actual practice in Cali- 
fornia agree with the results of the Pennsylvania 
State Experiment Station. Where there was little or 
no humus-forming material in the soil, acidulated 
forms gave the best results. Dr. Hopkins of the 
Illinois State Experiment Station and many others 
strongly advocate the use of finely ground, unacidu- 
lated phosphates with plenty of humus material, 
rather than the acidulated forms. (7),(8),(11). 



SOURCES OF POTASH. 

41. Potash is found as a chloride, or muriate, as 
a sulphate, and in a crude form called kainit. The 
latter contains 12i/^% actual potash. The muriate 
and sulphate analyze about 50^ actual potash. 
The Strassfurt mines in Germany supply the most of 
this product. 

The potash of manufactured fertilizers is never 
all animal matter. All commercial forms dissolve 
readily, so there is no danger of buying potash in 
unavailable form. It takes about two pounds of sul- 
phate, or muriate of potash to make one pound 
actual potash, or 10% sulphate to make 5% "actual." 

Wood ashes and stable manure are also sources of 
potash, obtainable, however, in very limited quan- 
tities. Wood ashes, unleached, will contain from 
4fV2% to 7% potash: mixed stable manure contains 
about 0.4% potash. 

The sulphate of potash is the best form in which 
to purchase. It has no ill effects on many plants, 



28 FERTILIZERS 

while the muriate or chloride form does. The sul- 
phate can also be used as a ''fixer" of ammonia in 
stables and manure pits, while the muriate might 
cause the escape of ammonia. 

AVAILABILITY. 

42. Buyers of fertilizers should always know the 
source and form of the different plant foods. This 
knowledge and the results obtained will determine 
their availability. Nitrogen from nitrate of soda is 
the most available form of any. Nitrogen from 
blood is more available than that from tankage. 

Phosphoric acid from acid phosphates (rock or 
bone) is more soluble than the non-acid phosphates. 

Steamed bone finely ground is more soluble than 
raw bone, as the latter is seldom finely ground. 

43. All nitrogenous substances become available 
easily. The most highly nitrogenous are the most 
readily available. For this reason it is difficult to 
say whether steamed bone or raw bone as a source 
of phosphoric acid is most readily available. The 
former is always more finely ground and the latter 
always higher in nitrogen, but as raw bone is usually 
quite coarsely ground, it is less readily acted upon 
by the various dissolving agents of the soil, notwith- 
standing its higher nitrogen content. The phos- 
phoric acid from tankage is more available than 
that from raw bone. Both the nitrogen and phos- 
phoric acid, as found in animal tankage and guanos, 
finely ground are very available forms. 

44. Soil moisture, root acids and fermentation, 
are the dissolving agents in all soils. The high tem- 
peratures of summer increase their action. Humus 
is essential to fermentation and to the carbonic acid 
in soil water which is a very active solvent. 



FERTILIZERS 29 

Roots cannot take up plant food unless it is pro- 
vided in solution, and different forms of fertilizers 
respond differently to these dissolving agents. Fine 
grinding is very important. As a rule organic forms 
are most available. There are some exceptions, such 
as sulphate of ammonia, nitrate of soda, and the 
acid phosphates. The latter act best in soils that do 
not contain enough lime, or iron, or other bases to 
cause rapid reversion to insolubilit3^ (33) (34). 

If the farmer knows the source and form of the 
nitrogen and phosphoric acid, he has a guide to their 
availability. 

All forms of potash as usually purchased in fertil- 
izers are readily dissolved and there is no danger of 
buying this ingredient in an insoluble form. 

45. Some substances, as lime carbonate and 
gypsum, make all fertihzers more available but they 
do not add plant food to the soil, and their use alone 
will in time exhaust a soil. Better results will be 
obtained by using commercial fertilizers with some 
humus material than by using either one alone, 
because the conditions of availability will be in- 
creased. 

46. Probable order of availability, nitrogenous 
substances : 

Nitrate of soda 

Dried blood 

Tankage (high in nitrogen) 

" (medium in nitrogen) 

" (low^ in nitrogen ) 
Guanos, same as tankage, unless greatly 

nitrified. 
Bone meal (finely ground) 
'* '' (coarse) 



30 FERTILIZERS 

47. Probable order of availability. Phosphates : 

Double super phosphate ) if watered 
Acidulated phosphates ) at once 
Phosphorus from tankage, high in nitrogen. 

" " guanos (as in tankage.) 

Thomas slag 
Steamed bone meal 
Raw 

48. Probable order of availability. Potassium, 
(potash) substances : 

( Sulphate 
All commercial forms / Muriate 

( Kainit 
Wood ashes 
Silicates (natural soil forms) 

49. The amount of potash and phosphoric acid 
carried by drainage and **run off" waters of good, 
bad and indifferent soils, bear directs on this ques- 
tion of availability. 

Table : — ''Matters dissolved by water from 100,- 
000 parts of various soils." (From Johnson's *How 
Crops Feed.') 



Soils 


Lime 


Mag. 


Pot. 


Phos. A. 


Silica 


Iron 


Organic 


Total, 


Rich 


16 


2 


13 


2 


11 


5 


53 


134 


Good 


34 


7 


8 


— 


22 


— 


36 


136 


Garden 


23 


1.5 




1.5 


38 


2 


30 


no 


Peat . 


164 


11 


47 


trace 


trace 


77 


449 


1095 


Poor 


10 


trace 




— 


— 


3 


18 


46 


Fair 


6 


1 




— 


2 


2 


23 


43 


Sandy 


1 


2.3 




trace 


trace 


— 


33 


39.5 



The matters least soluble are those found in the 
ash of plants. Where organic and volatile matter 
is carried in more appreciable amounts there is 



FERTILIZERS ^t 

greater solubility. There is no element less soluble 
than Phos. A. while potash is present in the drain- 
age water in quantity greater than a trace. Even 
silica is more soluble than phosphoric acid. 

CONCLUSIONS. 

50. The amount of soluble matter is greater in 
wet, peaty soils. Poor soils yield to water the least 
amount. Very rich soils, and well manured soils 
yield more to water than poor soils. From the 
table it is seen that where water extracted most 
organic matter, it extracted large quantities of other 
elements. Cultivation and irrigation use up organic 
matter rapidly. So the supply of humus materials 
must be constantly renewed. Humus and organic 
matter are the key to availability but are also prob- 
ably the means of exhausting other plant foods 
through the production of larger growth and crops. 
(86). 

INSOLUBILITY DESIRABLE. 

51. It is well known that the nitrates may easily 
be lost by leaching, because they are soluble. This is 
not the case with the phosphates, or phosphorus 
compounds, as these are always insoluble even in the 
most fertile soils. Numerous analyses of the "run 
off" waters show this. The nitrates being always 
available to the plant, stimulate its feeding powers 
and force it to act on such insoluble compounds as 
the phosphates, which, in turn, by yielding slowly, 
regulate growth and maintain for a longer time the 
soil's productive power. 

It can readily be seen that the loss would be 
many times greater if the phosphates and other com- 
pounds were soluble as well as the nitrates. 



32 FERTILIZERS 

The phosphoric acid of fertile soils is practically 
always insoluble. This is true of new lands, the rich- 
est and most productive known. It is nature's 
method. All fertile soils contain such bases as lime, 
iron and others that hold phosphorus in insoluble 
compounds from whence it is released only by the 
processes of plant growth and the chemical activities 
of fertile soils, due to a sufficient supply of humus, 
(35) (36). 



THE PURCHASE OF FERTILIZERS. 

52. Fertilizers should be purchased by the unit of 
plant food contained, with due consideration of its 
source, and not simply b^^ the ton or brand, as is 
usually the case. Each twenty pounds of a ton is 
called one unit or 1% ; 5% is five units or one hun- 
dred pounds. The value of a fertilizer depends en- 
tirely upon the amount and source of plant food con- 
tained. High grade analyses are worth more than 
low grade. Freight, sacking, storing and handling 
are fixed expenses on low or high grades. Therefore, 
high grades are cheapest. 

All the simple forms of fertihzer material, such as 
bone meal, tankage, blood, sulphate of potash, ni- 
trate of soda, etc., carry definite amounts or per- 
centages of their respective plant foods. ( 28 ) . 

53. If, for instance, blood is pure and cleanly 
handled, its nitrogen content is from 1S% to 14%, 
or 260 lbs. to 280 lbs. per ton. Pure bone meal (raw 
and steamed) varies in nitrogen from 1% to 5% and 
in phosphoric acid from 20% to 30%. If the nitro- 



FERTILIZERS 33 

gen is as low as 1% the phosphoric acid will be 
about 30%. If the nitrogen is as high as 5% the 
phosphoric acid will be about 20%: and so with all 
the simple materials. Their limits are known. 

It is quite possible with these limits known, to tell 
from the guarantee given by a dealer, whether the 
highest grade materials have been used in a given 
mixture. Suppose a dealer guarantees, as found on 
the bag, or tag : 

Nitrogen, 5% (from high grade blood) 
Phosphoric acid, 10% (from steamed bone meal) 
Potash (K2O), 2% (from the sulphate) 
High grade blood ccmtains at least 13% nitrogen 
pure, or 260 lbs. to the ton. To obtain the 5% or 
100 lbs. guaranteed will require \^^ of a ton of blood 
or 769 lbs. 

The phosphoric acid guaranteed is 10. % As 
steamed bone meal may contain 30%, to obtain 
10% will require fj of a ton or 666.66 lbs. 

Sulphate of potash usually runs 50 % actual (K2O) 
potash, so that the guarantee of 2% or 40 lbs. could 
be obtained from 80 lbs. of sulphate. Altogether the 
above guarantee of: 5% nitrogen, 

10% phosphoric acid, 
2% potash 
can be obtained from : 

Blood, 769. lbs. 

Steamed bone, 666.66 „ 

Sulphate of potash, 80. ,, 

or, total material 1515.66 lbs. 

Make weight to one ton 484.34 ,, 

2000.001bs. 



34 FERTILIZERS 

The foregoing illustration shows that from a given 
guarantee it is possible to prove v^hether a full ton 
of high grade materials was used or not. It would 
be interesting also to figure how much higher the 
analysis would be if the amounts of blood, bone and 
sulphate of potash were increased proportionately, 
so that there was no room for "make weight." 

It is only fair to the dealer to say that the 484.34 
lbs. "make weight" is not necessarily worthless filler. 
Low grade material may have been used. They are 
offered in the same market with the best. Blood can 
be so carelessty handled as to be full of floor refuse 
and foreign matter. The source of tankage influ- 
ences its grade. Both low and high grades are legit- 
imately bought and sold in the same market and the 
low grade often takes the place of "filler." To make 
the foregoing guarantee without filler, we could 
substitute 1150 lbs. of Thomas slag for 666.66 lbs. 
of steamed bone meal so the weights would be : 
Blood, 769 lbs. (a 13%= 99.9 lbs. or 5. % 

Thomas slag, 1150 " @18%=207. " or 10.25% 
Pot^a^sh^^^^f ^^ '' @50%= 40- " or 2. % 
Total 1999 lbs., or no room for filler. 

54. If ammonia is given instead of nitrogen, you 
can find its equivalent in nitrogen by multiplying 
by .825%; for instance, 5.5% ammonia equals 4.54% 
nitrogen. 

Do not confuse sulphate of potash with the actual 
(or K2O) potash. The sulphate usually runs about 
50% actual. So, it takes 2 pounds of sulphate to 
make one pound actual, or 2% sulphate to make 1% 
actual. 



FERTILIZERS 35 

The muriate contains about 48% actual potash 
and kainit about 12%. 

Bone phosphate must not be confused with phos- 
phoric acid. The latter is derived from bone phos- 
phate and is 45.8% of the bone phosphate; for 
instance, ^10% bone phosphate=18.32X phosphoric 
acid. 

55. Allowance must be made for phosphoric acid 
if it is derived from raw bone. It is then worth 
about 2c. per pound, while if taken from vSteamed 
bone would be w^orth fully 5c. per pound. In acidu- 
lated goods the phosphoric acid is in three different 
forms, with market values from 2c. up to 5V2C. per 
pound : the water-soluble being worth 5V^c. per 
pound, the insoluble, 2c. per pound.* 

The source is just as important a consideration 
as the quantity when considering the value. Both 
the quantit}^ of plant food (that is of nitrogen, 
phosphoric acid and potash) and its source, which 
determines its form, are really the only factors v^hich 
compose the value of a ton of fertilizers. (67) 



*No attempt is made to give market values. These fig- 
ures are simply for comparison of the difterent forms of 
phosphoric acid and are those usnallj^ used by State Agri- 
cultural Stations. 



36 FERTILIZERS 

Here are two analyses of different total value 
which will illustrate the foregoing : 

ANALYSIS I. 

Nitrogen in terms of ammonia, 5%. 
Equivalent in nitrogen (5X.825) 

4.13% or 82.60 pounds at 20c $16.52 

Phosphoric acid (from steamed bone) 

12% or 240 pounds at 5V2C 13.20 

Equivalent to bone phosphate 26% 
Potash (actual, K2O) 

S% or 60 pounds at 6c 3.60 

Sulphate of potash, 5.9% 

Total value of ton $33.32 

Note.— No account is taken of either the 26% of 
bone phosphate or of the 5.9% sulphate of potash as 
they are only repetitions of the 12% phosphoric acid 
and the 3% actual potash respectivel3^ 

ANALYSIS II. 

Nitrogen in terms of ammonia, 5V2% . 
Equivalent to nitrogen (5l^X.825) 

4.54% or 90.80 pounds at 20c $18.16 

Phosphoric acid (from raw bone) 

13% or 260 pounds at 2c 5.20 

Equal to bone phosphate, 31% . 
Potash, (actual, K2O) 

4% or 80 pounds at 6c 4.80 

Sulphate of potash, 7.95%. 

Total value of ton $28.16 

Although Analysis II is higher in its percentage 
of plant food, the form of the phosphoric acid is 
against it and cheapens it so much that the total 
value of the ton is considerably less. 

Either of these analyses might be offered to the 



FERTILIZERS 37 

grower for, say, $35 per ton and No. 1 would be the 
best buy for the grower, and No. 2 the best sale for 
the agent or manufacturer. 

It is quite possible for the nitrogen to be in cheap 
form also and worth considerably less than 20c. per 
pound. The nitrogen from raw bone is worth less 
than that from blood, or guano, or tankage. 

So the value of a ton of fertilizer is based upon 
the source or form of the nitrogen, phosphoric acid 
and potash, and the quantity of each. 

COST OF NITROGEN. 

56. Nitrate of soda, 96% pure, 16% nitrogen at 
$50 per ton. This yields 307 pounds of nitrogen, 
which at $50 per ton, equals 16.3c per pound or 
$3.24 per unit of 20 pounds. 

Dried, ground blood, analyzing 14% nitrogen, or 
280 pounds at $60 per ton, equals 21c. per pound, 
or $4.20 per unit. Market values change constantly. 
At times, nitrate may be worth $60 and blood 
worth $55 per ton. 

COST OF PHOSPHORIC ACID. 

57. Steamed, ground bone (not acidulated) at 
$35 per ton, containing 25% phosphoric acid (500 
pounds (equals 7c. per pound, less the value of 1% 
nitrogen (20 pounds) contained in steamed bone at 
20c. per pound would make the net cost of phos- 
phoric acid about $1.24 per 20 pounds, or 6V5C. per 
pound. Thomas Phosphate Powder, 17% phos- 
phoric acid, at $22.50 per ton, would cost $1.30 per 
unit, or 614c. per pound. 

COST OF POTASH. 

58. The sulphate yielding 49% actual potash can 
be bought for $60 per ton, making the actual potash 
cost 6c. per pound or $1.20 per unit, (20 pounds). 



38 FERTILIZERS 

COST OF COMBINATIONS 

59. Based on the foregoing, a tankage containing 
5.5% nitrogen and lci% phosphoric acid would have 
value as follows : 

5.5% (units) nitrogen % $4.20 per unit $23.10 

13% " phosphoric acid @ $1.24 16.12 

$39.22 

The nitrogen and phosphoric acid are in much the 
same form as found respectivel3^ in blood and 
steamed bone. 

A guano containing 5% nitrogen, 10% phosy^horic 
acid and 2% potash, would have a value as follows : 
5% (units) nitrogen, @ $4.20 (21c. per lb. )$ 21.00 

10% " phosphoric acid @ $1.24 12.40 

2% '' potash @ $1.20 2.40 

$35.80 

MOST ECONOMICAL FORM OF FERTILIZERS. 

60. If the price of nitrogen is the same in nitrates, 
and bone and blood, the cheapest is that which 
becomes available just as fast as the crop requires it, 
neither faster nor slower. Is nitrate too quickh^ 
soluble for the crop to use all of it before a part of it 
is carried away b}^ wasted water ? Is ground bone 
too slowly available or blood and bone just right? 
are questions to be answered by crop and con- 
ditions. 

If a form of plant food becomes available too 
rapidly, the moisture holding it in solution rises and 
evaporates, leaving this soluble^ valuable food on 
the top of the ground, whence it is partly lost by 
escaping surface waters and part carried back into 
the soil by penetrating moisture. That is whj^ slow- 
running water gives the most profitable irrigation. 



FERTILIZERS 39 

A * 'waste water" right on one ranch from another 
may become also a fertilizer right. 

If, however, some form of plant food, not so 
quickly soluble in running water as nitrate of soda, 
and yet readily soluble by soil moisture and root 
action, is used, there is much less actual loss during 
a season, and its effect is more sure and lasting. Yet 
there are times when a quick-acting fertilizer is 
needed. This would then be the most economical 
form. It depends upon the needs at the time, and 
the farmer should know enough about the nature of 
the different forms of plant food to exercise judg- 
ment in the selection. (46-48) (68-71). 

GENERAL PURCHASING PRINCIPLES. 

61. The market value of every brand depends 
upon the amount, or percentage of plant food con- 
tained, and its form. The nitrogen, phosphoric acid 
and potash each have their own market value per 
pound, and these must be known to the grower, in 
order to purchase economically. 

Be sure the food elements are of proper source and 
form to be available as fast as w^anted by the trees. 
This availability depends upon soil conditions. 

Purchase high grade materials. 

EXAMPLE OF FERTILIZER WORTH $6.50 PER TON. 

Fresh water mud, 2000 pounds, contains : 

30 pounds nitrogen (11/2%) at 20c $6.00 

41/2 " phosphoric acid (.23% ) at 51/2C... .23 

41/2 '' potash (.23%) at 6c 27 

$6.50 

EXAMPLE OF FERTILIZER WORTH $41.10 PER TON. 

Eighteen hundred pounds of blood and bone, 
containing 7% nitrogen and 10% phosphoric acid, 



40 FERTILIZERS 

added to 200 pounds of sulphate of potash, will make 

one ton, analyzing as follows : 

Nitrogen,6.3 % or 126 lbs. @ 20c $25.00 

Phosphoric acid, 9% or 180 lbs. @ 5V2C.... 9.90 

Potash (K2O) 5% or 100 lbs. @ 6c 6.00 

$41.10 

62. ILLUSTRATION NO. I— A HIGH GRADE 

FERTILIZER CONTAINING NO FILLER. 
ANALYSIS. OBTAINED FROM LBS. 

/1400 lbs. raw bone, 
(3.5% nitrogen 49.00 

^ aioTbs\' '^ r ^"^"^ ^^^ ^^^' ^^^^^^^ ^^^^ 
^ '^ ^ 1(96 % pure— 16 % 

\nitrogen) 61.00 

110.00 

Phosphoric acid Xfrr^ml'^'^^^ ^^^ ^^^ ^^^^ @ 

16%. j"^^ |23Xphosphoricacid.. 320.00 

Potash 5% \r 1 200 lbs. sulphate @ 

(100 lbs.) actualj *^^"^[50% actual potash.... 100.00 

COST OF ABOVE MATERIALS. 

1400 lbs. bone @ $35.00 per ton $24.50 

400 " nitrate...® 50.00 '' " 10.00 

200 " sulphate® 60.00 '' '' 6.00 

2000 lbs. Total $40.50 

ILLUSTRATION NO. II— A LOWER GRADE FERTILIZER 
CONTAINING 230 LBS. FILLER. 

ANALYSIS. OBTAINED FROM LBS. 

/1300 lbs. raw bone, 3.5% 

Nitrogen 5% If^Qjj^Witrogen 45.00 

(100 lbs.) ) 390 lbs. blood, 14% nitro- 

(gen 54.60 

99.60 



FERTILIZERS 41 

Phosphoric acid\^ /1300 lbs. bone, 23% 
15%, 300 lbs. /^^^^t phosphoric acid 299.00 

^""o^f In^'I^K^^^lfrom: 80 lbs. sulphate 40.00 

2%, 40 lbs. J ^ 

COST OF ABOVE MATERIALS. 

1300 lbs. bone @ $35.00 per ton.. $22.00 

390 *' blood @ 50.00 '' '' 11.70 

80 *' sulphate of potash @ 60.00 '' '' 2.40 

1770 
230 filler 



2000 lbs. Total $36.85 

Illustration No. I shows that if the analysis is 
high, only high grade materials can be used. Illus- 
tration No. II shows that if the analysis is low, 
either low grade materials or fillers were used. In No. 
II, high grade materials up to 1770 lbs. were used, 
and their value, pound for pound, is the same as in 
No. I. A filler used with high grade materials is 
equivalent to the use of low grade goods and the 
resulting analysis in No. II shows it. Less blood 
and bone could have been used in No. II, and more 
filler, but the resulting analysis would have been 
still lower. 

63. If, however, the fertilizer is acidulated, the per- 
centage of plant food may be low, as the weight of 
acid used displaces some of the material, yet the 
fertilizer should be considered high grade on account 
of the more soluble condition of its phosphoric acid. 
Here, the better form of plant food compensates for 
the smaller quantity. If the acid phosphate should 
revert to insolubility on account of the lime or other 
bases in the soil, its purchase would be equivalent to 
low^ grade materials, as the advantage of greater 



42 FERTILIZERS 

solubility is largely lost and the total amount of 
phosphoric acid purchased is small, yet its better 
distribution in the soil by water, may compensate 
for reversion. (8). 

THE * 'simples" and HOME MIXTURES. 

64. The "simples" are the original materials or the 
bases of which factory -mixed fertilizers are composed. 
They are such materials, as nitrate of soda, pure 
blood, sulphate of ammonia, potash, salts, bone, 
phosphate rock, super phosphates, etc. Tankage 
and the guanos are "simples," as they are the bases 
of manufactured brands. There are low and high 
grades of the "simples" as well as of brands, and 
guarantees should always be obtained by the buyer. 

Sometimes these materials can be purchased 
cheaper separately than when mixed. Such is the 
case if the buyer is near a seaport or near the source 
of the material. The advantages are, the buyer 
knows what he is getting ; he buys only the ingre- 
dients he needs and he bu3^s direct. Such advantages 
how^ever, do not always hold if the quantity wanted 
is less than a carload. 

If, however, a complete fertilizer is needed, it is 
better to buy of a reliable manufacturer, as the goods 
are then mixed and blended more evenly and cheaply. 
If several ingredients are needed and these can be 
purchased to advantage separately, it would be 
better to apply them separately than to attempt 
home mixing, for a shovel and a barn floor will not 
mix materials evenly and uniformly without extreme 
care. 

As a rule home mixing pays when compared with 
the purchase of low grade brands. If the manufac- 



FERTILIZERS 43 

turer offers high grade fertilizers it is time and 
money saved to UvSe them. 

WHY THE ANALYSIS DOES NOT ADD TO ONE HUNDRED 
PER CENT. 

65. The Vermont Agricultural Experiment Sta- 
tion Bulletin No. 47 sa3'S : ''The question is often 
asked why the plant food contained in a fertilizer 
does not add up to 100. For instance, the average 
Vermont goods this year contain in a hundred, 2.22 
pounds nitrogen, 10.93 pounds total phosphoric 
acid and 3.46 pounds of potash, a total of 16.61 
pounds. Of what did the other 83.39 pounds con- 
sist, and is it needed for plant food ? It will be re- 
membered that nitrogen is a gas, and phosphoric 
acid and potash respectively strong acid and alkali, 
and they can only be useful in combined forms. If 
medium grade materials were used in the manufac- 
ture of the average fertilizer, as stated above, it 
might be made up as follows : 
440 pounds of organic matter (blood, tankage, etc.) 
850 pounds of ground S.C. rock and sulphuric acid. 
110 pounds of muriate of potash. 

1400 lbs. 

This would leave 600 pounds, or 30 per cent of 
the gross weight in every ton for moisture, dirt and 
useless material on which freight, mixing and bag- 
ging expenses, storage, etc., must be paid by the 
consumer. 

A complete analysis of the above 1400 pounds 
would probably resemble the following : ' 



44 FERTILIZERS 

Water 16.0 (combined with organic 

matter and sulphuric acid) 

Nitrogen 2.0 

Phosphoric acid 10.6 

Potash 2.9 

Volatile and organic 33.0 (Combined with nitrogen) 

Gypsum 16.0 (Formed by action of 

sulphuric acid on rock.) 

Lime 7.1 (Left combined with phos- 
phoric acid) 

Sand 4.0 (Impurity prosp. rock.) 

Chlorine and Salts.. 3.0 (Combined with potash.) 

Miscellaneous 5.2 

100.0 

Of the ten substances which compose the above 
100 per cent, only three are of interest to the farmer. 
The value of the whole ton is based on the value of 
the nitrogen, phosphoric acid, and potash, onh^ 

In raw bone, for example, it is impossible to give 
a farmer the S% nitrogen and the 24% phosphoric 
acid contained without giving him the 73% of lime, 
gelatines and fats, etc., found in bone, for these sub- 
stances are in combination and the process of separ- 
ation would be too costly. 

HOW TO UNDERSTAND A FERTILIZER ANALYSIS 

66. Manufacturers often state the analysis of their 
fertilizers in a confusing way. They use two terms 
to express the same thing. Nitrogen and ammonia 
both mean one thing, and the analysis should read, 
for example, ''nitrogen 4.95% equal to ammonia 
6%," showing that there is not both the 4.95%, and 
the 6%, but onty one or the other. That the one 
repeats the other. Multipty the percentage of am- 
monia by .825 and the result will be the equivalent 



FERTILIZERS 45 

in nitrogen, as for example, 6% ammonia, X.825= 
4.95% nitrogen, It takes 4.95% nitrogen to equal 
6% ammonia. In figuring the value of a ton in 
dollars and cents, if the nitrogen from blood or 
nitrate of soda has ^i market value of 16 cents per 
pound, its equivalent in ammonia is worth onl3^ 
13Vo cents per pound. Only one should be included 
in the estimate. 

And so w^ith the terms bone phosphate and phos- 
phoric acid. The phosphoric acid comes from the 
bone phosphate. For example, it takes 30%) of bone 
phosphate (sometimes called 'bone phosphate of 
lime') to make 13.74% of phosphoric acid. When 
both terms are employed by the manufacturer 
the v^ords ''equal to" should be used thus : "Bone 
phosphate of lime, 30%, equal to phosphoric acid, 
13.74%," which means that the manufacturer used 
600 pounds of bone phosphate or bone — 30% of the 
ton— to obtain 13.74% of phosphoric acid. 

Multiply the percentage of bone phosphate by 
.458 and the result will be the equivalent in phos- 
phoric acid thus: 30% bone phosphate of lime 
X. 458=13. 74%) phosphoric acid. 

In estimating the value, for comparison, of a ton 
in dollars and cents, phosphoric acid from fine bone 
is worth about 5^} cents per pound, while its equiva- 
lent in terms of bone phosphate is worth onh^ 2V2 
cents per pound. Only one should be included in the 
estimate. 

Where the "soluble," the "reverted," and the 
"insoluble," and the "total" phosphoric acid are all 
given, it is understood that the "total" is made up 
of the first three mentioned. 



46 FERTILIZERS 

The sulphate and muriate of potash will analyze 
in round numbers about 50% actual potash (some- 
times expressed as K2O). In other words it takes 
two pounds of sulphate or muriate of potash to 
make one pound of actual potash (K2O). When an 
analysis states: ''Sulphate of potash 8%, actual 
potash 4%," it means simply that there is only 4% 
of actual potash in the ton, or 80 pounds, and that 
the manufacturers used 8% or 160 pounds of sul- 
phate of potash to get it. The actual potash is 
worth about six cents per pound, while the sulphate 
is worth only three cents per pound. 

When both terms are used in stating the analysis, 
only one of them should be included in the estimate 
of the value of a ton. 

COMMERCIAL VS. AGRICULTURAL VALUE. 

67. Farmers frequently confound the agricultural 
and commercial value of a fertilizer. If one is high 
it does not necessarily imply that the other must be. 

The commercial value of any commodity is its 
market price, its purchase price, and depends entirely 
upon "supply and demand." 

The agricultural value of a fertilizer is its abilit3^ 
to improve the fertilitj^ of the soil and the condition 
of the crop in question. 

As an illustration, suppose a steady, long-lived 
food were wanted for some perennials as an orchard, 
blood would answer the purpose while nitrate of 
soda would be soon exhausted or lost by leaching. 
Now, if the price of both nitrate and blood is about 
the same, the agricultural value of blood is far 
greater. If a quickl^^ acting manure was wanted, 
the nitrate of soda would have the higher agricul- 
tural value. 



FERTILIZERS 47 

Again, if phosphoric acid was not needed for a 
particular soil and crop, it would then have no agri- 
cultural value in that case, but would still have a 
market, or commercial value. 

In the selection of a fertilizer, the agricultural 
value should be considered first and the commercial 
value second. Good results are of first importance 
and depends on the agricultural value. 



THE USE OF FERTILIZERS. 

68. In order to use fertilizers intelligently^ it is 
necessary to know the specific action of the three 
plant foods; nitrogen, phosphoric acid, and potash, 
their sources, and when and how to apply them. 
The few experiments which have been made with 
various fertilizers on citrus trees confirm the same 
general principles that hold with reference to other 
crops. They will be briefly stated. 

EFFECT OF NITROGEN. 

69. The presence of available nitrogen is shown 
by a dark, healthy, green color of leaves and stems. 
Growth is vigorous. The feeding power of the plant 
is increased. If an excess of nitrogen is available at 
the time of flowering, and the suppl3^ of phosphoric 
acid insufficient, the bud and bloom and fruit will be 
imperfect and the total amount of fruit lessened. 
The fruit will then be rough and thick-skinned. 
Constant use of stable manure, without the addition 
of phosphoric acid, will produce thick-rind fruit. 
The size of fruit may be increased by nitrogen. A 



48 FERTILIZERS 

lack of nitrogen is shown by yellow trees and 
small growth, or lack of vigor. Nitrogen will not 
give its best effect unless phosphoric acid and potash 
are present. 

EFFECT OF PHOSPHORIC ACID. 

70. Phosphoric acid helps a plant to assimilate 
other plant foods. It is also essential to the final 
maturity of the plant or its seed production, and 
hastens this maturity, if abundant and available at 
blossoming time. Although the navel orange con- 
tains no seed, phosphoric acid is as essential as 
though it did. What usually thus goes into seed is 
needed elsewhere in the development of the fruit. 

If maturity is hastened by the presence of an 
abundance of available phosphoric acid at the time 
of blossom, the early ripening of the orange can be 
likewise effected, though plant food effects are 
directly dependent upon culture and water. 

Phosphoric acid will not give its best effect unless 
there is some nitrogen present. Plants well supplied 
with phosphorus, vegetate faster and are earlier. 
If an over abundance of nitrogen is making fruit 
rough or ''puffy, " phosphoric acid will help to 
correct this. Its tendency is to make thin-skinned, 
smooth fruit. 

EFFECT OF POTASH. 

71. Potash is necessary to the full development of 
the wood of the tree. If potash is wanting, the 
wood not only will not mature, but is subject to 
frost and disease ; neither can immature wood carry 
much fruit. Potash aids in the formation and trans- 
fer of starch, first to the leaves and from there to 
the flesh of the fruit, which would be imperfect other- 



FERTILIZERS 49 

wise. The best authorities agree that potash in- 
creases the sweetness of Iruit and their shipping 
quality. (19). 

Plants, undoubtedly, begin their growth in the 
spring on the food that was stored in their tissues 
the previous fall. Potash is largely the source of 
this stored food, and is consequently necessary to 
the full growth and health of the tree. 

It is generally admitted, however, that applica- 
tions of potash are unnecessary in most California 
soils. Man}^ cases are reported in which heavy 
applications of wood ashes gave no appreciable 
results. If the land in question has been continuously 
cropped many years, as in a fifteen or twenty years' 
old orchard, the potash question should be carefully 
investigated. 

72. Besides its effect on the plant as potash or 
potassium, increasing the starches and sugars, the 
use of potash salts has another indirect fertilizing 
effect similar to that of lime and common salt, by 
causing the soil to yield more quickly, its natural 
and other plant foods. Potash salts while neutral, 
may increase the alkalinity of the soil and thus 
foster and encourage the work of nitrifying and 
other bacteria which transform decayed organic 
matter into useful forms. Carbon is one of the result- 
ant products, so that the carbonic acid which soil 
moisture carries, may be increased thus making it 
a better solvent of many other plant foods. This 
increased alkalinity of the soil may therefore increase 
the formation of the nitrates and more vigorous 
growth will result. Potassium as such, did not pro- 
duce this result, which was due rather to the added 



50 FERTILIZERS 

alkaline effect of the potash salt. Lime carbonate or 
gypsum or common table salt might have produced 
the same eifect. 

GENERAL PRINCIPLES. 

73. In a general way, both phosphoric acid and 
potash influence the quality and fineness of the fruit, 
while nitrogen produces the vegetable tissue, such as 
the skin and pulp of fruit, and leaves and bark of 
trees. The juice and seed and smoothness and the 
number of the fruits, and earliness, can be increased 
by phosphoric acid and potash . The size and coarse- 
ness and large growth and late maturity can be 
secured by the excessive use of nitrogen. These effects 
are noticeable only when there is an excess of one 
element and a de£ciency of the others. 

AVOIDING PURCHASES OF UNNECESSARY FERTILIZERS. 

74. Knowing the specific effect of the three essen- 
tial plant foods, as just stated, and by observing the 
condition of an orchard, a grower may frequently 
avoid the purchase of unnecessary plant food. 

Bottom lands are usually rich in nitrogen. Sandy 
soils are apt to lack potash. Cla^^ soils usually con- 
tain much potash, etc. Coarse, thick-rind fruit, with 
deep green color of leaves and a too vigorous growth 
may indicate that nitrogen could profitably be 
omitted one season, or used very lightl3^ An over 
abundance of smooth fruit on yellow trees of slow 
growth may indicate an excess of phosphoric acid 
for the nitrogen present, or a lack of nitrogen. Iron 
is as essential as nitrogen to green leaves and stems, 
so yellow foliage may, in rare cases, be caused by the 
absence of iron as well as nitrogen. The amount of 
iron necessary for green foliage is so small, that lack 



FERTILIZERS 51 

of nitrogen is usually the cause of yellow color in 
citrus orchards. 

A careful record of previous applications, nameh^ : 
The amount and analysis of the fertilizer, time of 
application, and its effects on growth and crop will 
be a guide to selection. 

TIME TO APPLY FERTILIZERS. 

75. In the book of nature we read that growth is 
dormant for some months preceeding the blossom 
and fruit setting period. This is naturall^^ the time' 
of most moisture in soils, which with root acids and 
fermentation, are rendering available the unavail- 
able plant foods natural to the soil. So, when the 
important time of blossom comes, the plants have 
their greatest store of available plant food to draw 
upon, so that fertilizers should be applied long 
enough before the blossom time to become avail- 
able. 

76. Nitrate of soda requires the least time. Blood 
requires more time than nitrate, and raw bone more 
time than blood. Coarse bone, and hoof and horn 
meal, are slowest in their action. Acidulated phos- 
phate acts more quickly than any other form (that 
is the soluble portion.) Steamed, fine ground bone, 
used with some ammoniate, is next in order, while 
fatty, raw bone takes still more time to decompose. 
(46-48). 

Many apply a part of the fertilizer in early sum- 
mer. This is intended to feed the latter growth of 
tree and crop. It is a practice that undoubtedly 
gives better results and is gaining in favor. 

77. Acidulated forms should always be applied 
just before an irrigation or rain, for then the water 



52 FERTILIZERS 

will carry the soluble portion to the deepest roots, 
wherever, in fact water can go. There, reversion to 
insolubility may and probably does occur in a few 
days, but the phosphoric acid is where the roots can 
act on it directly. (8) (35). 

Nitrate of soda should not be applied in late fall 
or winter months while growth is dormant, as it 
would probably be leached awaj- before the tree could 
take it up. Organic forms should be applied in Janu- 
ary or February. 

AMOUNT TO APPLY. 

78. The quantity of fertilizer that should be used 
varies with the conditions. It depends upon : 

1. The percentage richness of the fertilizer. 

2. Record of past experience. 

3. Natural richness of soil. 

4. Age and number of trees per acre. 

5. Kind of tree or crop. 

One popular way of estimating the amount to use 
is to say one pound of high grade fertilizer to each 
year of age of the tree. This, while very inaccurate, 
gives good results, but the practice of citrus culture 
has demonstrated the wisdom of using considerably 
more than this amount, probably two pounds for 
each year of age of citrus trees will be fully war- 
ranted in most cases. 

This is particularly true of trees over twelve and 
fifteen years old. If the fertilizer is low grade, the 
amount used should be increased. 

If trees have been topped for budding or very 
severely pruned, the amount may be reduced accord- 
dingl3^ 



FERTILIZERS 53 

METHODS OF APPLICATION. 

79. The best method of application is undoubt- 
edly by drill, on account of its labor saving and 
uniformity. 

Though not over five inches deep, the drill covers the 
fertilizer, which can be placed deeper by subsequent 
plovyring. The use of drill obviates the unpleasantness 
of appl^ang in any winds which may prevail. No 
hand process is so uniform or inexpensive, though 
some other methods place the fertilizer deeper. It is 
well worth the extra cost to hire a hand to follow 
each plow furrow and place the fertilizer that depth. 

STABLE MANURE. 

80. An average analysis of one ton of horse 
manure would be : 

Nitrogen— 0.50% or 10 lbs. of a ton at 20c $2.00 

Phosphoric acid— 0.25% or 5 lbs. of a ton at 6c. .30 

Potash— 0.40% or 9.6 lbs. of a ton at 6c 58 

$2.88 
The commercial value of the plant food is then 
about $2.88 per ton. Barn yard manure when cared 
for properly, is a most profitable form of fertilizer, 
because of its humic and mulch value. It is a bi- 
product of every ranch, costs nothing, and is worth 
about $2.88 per ton for the actual plant food con- 
tained. In dry countries it has a still greater value 
in its moisture saving properties. As a source of 
humus it is worth considerably more than its plant 
food value. 

81. The more decomposed the manure, the more 
available is its plant food. If, however, decomposi- 
tion is too rapid, the nitrogen escapes in the air as 
ammonia, and humus-forming matter is destroyed. 



54 FERTILIZERS 

High temperatures produce rapid decomposition, 
especially in a loose heap, so that the rate of deca^^ 
maybe regulated by compacting the heap and sprink- 
ling with water to exclude the air and reduce the 
temperature. If compacted too tightlj^ decomposi- 
tion ma\^ be too slow. Moderate fermentation is the 
object desired. Loss of nitrogen, as ammonia, may 
be detected by the strong odor arising, from the heap. 

If it is desired to obtain the benefits of the plant 
food in manure quickl3% it should be stored under 
cover to prevent loss by leaching, and the tempera- 
ture kept down by frequent wetting, and air ex- 
cluded by settling the heap : decomposition may 
thus take place with a minimum loss of ammonia. 
If from one to two pounds of either gypsum, or sul- 
phate of potash be sprinkled on the heap each day 
as it accumulates from one or two animals, the am- 
monia is converted to the sulphate form and thus 
prevented from escaping. The gypsum must be 
moist for this use to be effective. 

If, however, it is not desired to get the benefits of 
plant food quickl}^ the manure had better be applied 
fresh and incorporated with the soil at once. Decom- 
position may be slower in such cases, but loss of 
ammonia is surely prevented and a much better 
mulch obtained. This is the most practical method. 

GREEN MANURING. 

82. The object of sowing the leguminous, or pod- 
bearing plants is chiefly four-fold. 

1. For humus, which is always necessary for anj^ 
form of crop because of its various functions in the 
soil, such as : (a) nitrification; (b) Rendering insol- 
uble forms of plant food available by the process of 



FERTILIZERS 55 

decay, (29) ; (c) Increasing the moisture holding 
power and friabihty of the soil. (90.) 

2. To obtain the nitrogen which they gather 
during their growth. (30). 

3. To set free unavailable plant foods by the 
direct action of their roots. (Insoluble substances 
are coroded, and dissolved and taken up into the 
plant tissue and later become available as the plant 
decays.) 

4. To prevent soil washing and leaching by win- 
ter rains. 

83. The common vetch (Yicia Sativa) is at pres- 
ent the most popular legume for the California orch- 
ardist. Field peas, some clovers, and other varieties 
of vetch are also used. Barley and other non legu- 
minous plants have not the same nitrogen gather- 
ing power but are beneficial as far as their roots set 
free unavailable forms of potash and phosphoric 
acid. 

The volunteer non-leguminous plants and weeds 
such as alfilerea mallow, foxtail and others, are per- 
haps as beneficial as legumes plants for their humus 
value and root petetration and while it is not cer- 
tainh^ known just now how much nitrogen may be 
added by various legumes it is probably safe to 
assume that the}^ add some and for this reason are 
preferred to the non-leguminous plants. 

COVER CROPS AND WATER. 

84. It is well known that the winter cover crops 
use up a good portion of the rain that falls so that 
comparatively the clean culture orchards begin the 
dry season with more moisture in the ground. While 
this loss is usually more than compensated for by 



56 FERTILIZERS 

the many advantages of the cover crop already 
cited there may be special situations where the 
water is all necessary to the orchard. If the water 
right were limited by the capacity of the ditch or if 
the season's rainfall were too short to risk the loss 
of water necessary to a cover crop, straw or dam- 
aged hay could be hauled and spread and plowed 
under as a fair substitute. Any amount of humus 
could be added in this way and all of the rainfall con- 
served for the summer months. 

SUMMER COYER CROPS. 

85. It is difficult to maintain the supply of humus 
material under conditions of constant irrigation and 
cultivation. Cover crops have been raised in sum- 
mer as well as in winter in a few instances. Horse 
beans and cow peas have been used for the purpose. 
They are planted in Ma3^ or June and turned under 
in August, and while the results are undoubtedly 
beneficial the extra water necessary will prevent the 
practice from becoming general. 

The United States Government has found by ex- 
perimentin California orchards, several legumes that 
promise a greater tonage of green matter, under 
equal conditions, than the present Oregon or com- 
mon vetch so generally used. These include two 
species of Vicia; one pea, and one bean. So that 
this phase of agriculture will no doubt be improved 
and modified from time to time. 

The green manure wanted b^^ orange growers is 
one that will grow quickly as California winters are 
short and dry, and growers cannot afford to let the 
ground rest undisturbed ver3^ long. 



FERTILIZERS 57 

HUMUS FERTILIZERS— NECESSITY OF 
ORGANIC MATTER. 

86. Humus is decayed organic matter. It is neces- 
sary for fertility, because all the nitrogen in soils 
comes from either an animal or vegetable source. 
(Very minute quantities are absorbed from the air 
as ammonia and as nitrogen). The nitrates come 
from humus. They are water soluble and can be 
taken up by the roots. Thus the plant gets its 
nitrogen. (15) (29) 

All fertile soils are rich in organic matter. The ex- 
ceeding richness of new lands is due to the humus 
deposited by succeeding crops for generations. This 
is true of both the high mesa and the valley land. 
It is possible to use some chemical form of nitrogen 
and raise a plant, but it is expensive, requires close 
watching and is not practical. The nitrogen from 
organic fertilizers is yielded to the plant gradually, 
with greater certainty, and is more lasting. 

87. Organic manures, whether of blood and bone, 
or stable manure, or green cover crops, not only 
furnish nitrogen to plant life, but their decay gen- 
erates several well known acids, notably carbonic, 
which combine with the soil moisture and dissolve 
other forms of plant food. Without these acids, 
phosphorus, potash and other necessary elements 
would not be so available to the plant. Direct root 
and water action would then have to do the work 
alone, and the plant would not thrive so well. Hu- 
mus influences the availability of the phosphoric 
acid and potash and converts them into forms more 
readily utilized by the plant. (49-50). 



58 FERTILIZERS 

88. Organic fertilizers lighten soils. Their decay 
leaves the soil open and porous. More oxygen is 
thus admitted, which gives more life to the micro- 
organisms, which, after all, are the cause of all fer- 
tility. Better cultivation is possible in such soils. 
Light, porous soils are more retentive of moisture. 
Thus, organic matter literally builds up a soil. It 
increases its depth. A 'Svorn-out" soil is simply a 
soil devoid of humus. It is lifeless. Liberal applica- 
tions of organic matter restore it and change it from 
a tax to an income. 

89. Humus forming-materials are, therefore, 
necessary to successful and practical farming. The 
best results from inorganic fertilizers, such as rock 
and acid phosphates, Thomas slag and sulphate of 
potash, are obtained when they are used with ma- 
nure, or blood, or blood and bone, or a green cover 
crop turned under. 

90. "Humus is not only the principal source of 
nitrogen in soils, but it influences to a marked ex- 
tent the available potash and phosphoric acid. 
Humus forming materials, like green manures and 
yard manure, have the power, when they decompose 
in the soil, of combining with the potash and phos- 
phoric acid of the soil and thus converting them into 
forms which are readily utilized by the plants. "(82). 



CULTIVATION AND FERTILIZERS. 

91. Cultivation increases the availability of fer- 
tilizers by aiding nitrification and by saving soil 
moisture. All organic forms must first decay and 
then be turned into nitrates (nitrification), and 



FERTILIZERS 59 

other salts before water can carry their elements to 
the roots of plants. (29). 

The decomposed matter (humus) is attacked by 
nitrifying bacteria and these require oxygen for 
their work. Cultivation increases this supply of 
oxygen so that nitrification proceeds faster, and 
better growth results. The more frequent and deep 
the cultivation, the better the nitrifying bacteria can 
work. The size of fruit can be increased in this way, 
or a short vSeason made equal to a long one. 

Cultivation therefore uses up humus very rapidly 
so that the supply must be frequently renewed. The 
extra growth and yield are probably proportional 
to the supply of humus and frequency of cultivation. 

92. This principle of aiding nitrification applies 
to all forms of animal and vegetable fertilizers such 
as yard manure, blood, raw bone, guano, tankage, 
and peas and clover, planted for their fertilizing 
value when ploughed under. 

Frequent, deep cultivation increases the supply 
of water in soils. Several well-known acids, result- 
ing from decomposition, unite with soil moisture 
and dissolve what ordinary water will not. Insol- 
uble forms of fertilizers, such as phosphate of lime 
and silicate of potash, are probably thus made 
available to the plant. 

93. Moist soils swell and are more permeable. 
Roots can develop faster in them, and the fertilizers, 
applied to the top, six inches, as they gradually dis- 
solve, can be carried more easily and deeply, increas- 
ing the feeding area of the roots and the develop- 
ment of the plant. 

Frequent and through cultivation, helps and 
multiplies these beneficial effects of soil moisture. 



60 FERTILIZERS 

IRRIGATION AND FERTILIZERS. 

94. Plants can take up food, onlj^ when it is pro- 
vided in solution. The food maj be dissolved by 
water, or by direct root action, or by the process of 
fermentation, v^hich is almost constant in all soils. 
In either case water is essential, and the common 
carrier, and the way in which it is used, seriously 
effects the results of fertilization. Especially is this 
true because the top foot of soil contains the most 
valuable fertilizing ingredients. 

There are three kinds of water in soils : free water 
which moves by gravity ; hygroscopic w^ater, detect- 
able only by laboratory methods even in the dryest 
earth, and capillary water, which moves by the 
power of attraction between particles of matter. 
This capillary water is what plants feed and depend 
upon mainly. It travels up and down freely with 
very little motion, sideways, carrying with it the 
soluble fertilizers. 

95. It is useless to apply fertilizers on dry ground 
that is not dampened by irrigating water, as for 
instance ; far under very old trees or on the midway 
spaces in young orchards where furrows are not 
made. 

As moisture evaporates at the surface, it is con- 
stantly supplied from below by the capillary move- 
ment. The dissolved fertilizers contained, remain at 
the surface from which the water evaporates ; hence 
they accumulate so that top soils are always the 
richest. The next rain or irrigation carries the plant 
food down onl^^ to rise again as evaporation pro- 
gresses at the surface. There is thus an oscillation 
of water containing many kinds of plant food, up 
and down many times a year. 



FERTILIZERS 61 

96. Certain forms of fertilizers, such as the ni- 
trates (both soda and potash) ammonium sulphate, 
the sulphate of potash, and the acid and super-phos- 
phates are easily carried by water. If applied just 
previous to an irrigation they go to the deepest 
roots, or wherever water can go. If there is any 
waste water a part of them is lost. 

If the grade from the flume is very steep for fifty 
feet or more, the trees in that space will be the first 
to turn yellov^, although they are nearest the flume 
and receive the most water. The nitrates have been 
washed to lower levels. Manure or straw should be 
used in such places so that the water will move 
more slowly and the nitrates retained where they 
belong. 

On account of the solubility of many forms of 
plant food, irrigation water should be handled very 
carefully. Do not turn a heavy head of water into a 
furrow until after the furrow is soaked a little and 
the fine earth compacted. This will lessen washing. 
The ideal movement of water is up and down, with 
as little movement on the surface as possible. In 
this way the rich top soil with its humus and fer- 
tilizers will be retained where it belongs. 

VALUE OF SOIL ANALYSIS. 

97. Soil anaWses are valuable for determining in 
a general wa^- the needs of a crop. The greater the 
number of samples examined, the more accurate will 
be the information obtained. Very little can be con- 
cluded from one sample. Taken in connection with 
the appearance of trees and vegetation raised on the 
soil, many a useless expenditure for fertilizing ingre- 
dients may thus be avoided. 



62 FERTILIZERS 

If samples of soil be taken according to the direc- 
tions of the State Expeiiment Station the results 
may be relied upon as indicating that soil's capacity 
for various crops. This information, with the 
owner's knowledge of previous treatment, together 
with the appearance of the vegetation and growth 
gives a pretty thorough diagnosis. Each of these 
sources of information acts as a check or supple- 
ments the other two. 

98. Soil analysis should be interpreted by an ex- 
pert for where yV of 1 % would be considered a suffic- 
iency of some element, it would be regarded as a 
deficiency of other elements. A soil containing % of 
1% humus is lacking in that substance, while that 
amount of potash or lime would be considered 
ample for fertihty. (100). 

Again, soil anaWses may reveal the presence of 
some poison, such as carbonate of soda, or chlorine, 
in the midst of otherwise fertile conditions. An ex- 
cess of either acid or alkali can likewise be deter- 
mined. Plant food may be present in abundance and 
yet the results be unsatisfactor}^ on account of poor 
cultural conditions, or lack of humus. This, also, 
soil analysis would reveal. 

Whenever there is uncertainty about the needs of 
crops or orchard, soil analysis should alwa^^s be 
taken. One element, only may be lacking and thus 
discovered, and the purchase of the element unneces- 
sary be avoided. The California State Experiment 
Station has advised farmers that sufficient potash is 
present in nearly all California soils. General experi- 
ence has confirmed this statement, thus saving the 
farmers many dollars annuall^^ 



FERTILIZERS 63 

99. The mechanical analysis of soils is always 
important. Most California soils are sedimentary 
and composed of irregular strata varying in thick- 
ness from a few inches to many feet. They may be 
impenet ratable and poorly drained, or too open and 
coarse to hold the requisite moisture. The subsoil 
conditions should be known. (20-21-22). 

100. The following table is compiled mainly from 
the records of the California State Experiment Sta- 
tion and from Dr. Hilgard's book, *'Soil," which 
state quite positively that when the chemical deter- 
mination of certain elements in soils run below a 
certain amount that soil is quite sure to be unpro- 
ductive. These figures are the result of a large num- 
ber of analyses representing years of work. 

ADEQUATE PLANT FOOD. 



RICH 


ADEQUATE 


INADEQUATE 


PER CENT. 


PER CENT. 


PER CENT. 


Humus in soil 2.00 


1.00 


0.85 


Nitrogen in humus 9.00 


4.00 


2.00 


Lime 1.50 


1.00 


0.40 


Phosphoric acid 0.20 


0.10 


0.05 


Potash (K2O) 1.00 


0.45 


0.25 



These figures will vary for different crops. Ade- 
quacy for one kind of crop might be inadequate for 
another. But they are averages for a large number 
of determinations and very suggestive. It has been 
well established also that when the per cent, of lime 
is high, much smaller amounts of the other plant 
foods will sufiice. 



64 FERTILIZERS 

FERTILIZING VALUE OF STRAW, STABLE MANURE, 
ORANGE CULLS, AND CERTAIN LEGUMES, f 

101. N. P.A. Pot.* 

|Pea vine hay 3.00 

iVetch hay 2.55 

Burr clover hay 2.68 

Alfalfa hay 2.19 

Wheat straw 0.59 

Stable manure 0.50 

Orange culls 0.18 

*(Nitrogen @ $4.00 per 
per unit and potash @ $1.25 per unit.) 

fThe value of the above materials for humus is 
probably equal to, or greater than their fertility 
value as judged by the results obtained from their 
use. 

ilt is assumed in the table that the pea, vetch and 
burr clover were raised as a cover catch crop in the 
orchard, and that this nitrogen is all gain, which 
fact is not yet established beyond doubt. Their 
phosphoric acid and potash are not reported, as 
what they take of these from the soil is returned 
with them. 







$12.00 






10.20 






10.72 


1.51 


1.68 


11.37 


0.12 


0.51 


3.12 


0.25 


0.50 


2.87 


0.12 


0.21 


1.10 


[nit. Phos. acid @ $1.00 



INDEX. 

Acidulated Phosphates 23 

Adequate plant food 63 

Agricultural value 46 

Alfalfa, fertilizing value 64 

Analysis adding to 100 per cent 43 

Analysis of fertilizer. How to understand 44 

Analysis of soil 61 

Applying fertilizers, Time for 51 

Applying fertilizers, Amount , 52 

Applying fertilizers, Method 53 

Applying fertilizers deeply 9 

Availability 28 

Availability, Order of 29 

Basic slag 25 

Bone 25 

Burr clover, fertilizing value 64 

Canadian peas, fertilizing value 64 

Commercial value 46 

Clover crops and water 55 

Culls, fertilizing value 64 

Cultivation, relation to fertilizers 58 

Drainage of soils 16 

Economical form of fertilizers 38 

Effects of plant foods 50 

Essential plant food 17 

Example of fertilizer worth f 6.50 per ton 39 

Example of fertilizer worth $41.10 per ton 39 

Fertilizers, purchase 32 

Fertilizers, source 19 

Fertilizers, use 47 

General principles, effect of fertilizers 50 

Green manure 54 

High grade fertilizer, example 40 



INDETX. 

Home mixtures 42 

Humus (organic matter) 57 

Insolu bility , desirable 31 

Irrigation, relation to fertilizers 60 

Lower grade fertilizers, example 40 

Manure, green 54 

Manure, stable 53 

Manure, fertilizing value (54 

Most economical form 38 

Nitrification 21 

Nitrogen, cost of 37 

Nitrogen, effect of 47 

Nitrogen, from air 21 

Nitrogen, sources of ..19 

Nitrogen from organic sources 22 

Nitrogen cycle 20 

Nitrate of soda and carbonates 22 

Orange culls 64 

Organic matter (humus) 57 

Peas, green manure 54 

Phosphate guanos 26 

Phosphoric acid, cheapest form 26 

Phosphoric acid, cost of 37 

Phosphoric acid, effect of 48 

Phosphoric acid, sources of 23 

Plants, general 5 

Plant food, amount necessary 63 

Plant food U 

Plant food "essentiar* 17 

Plant food, air derived 11 

Plant food, soil derived 11 

Plant food, definition 17 

Potash, effect of 48 



INDETX. 

Potash, cost of 37 

Potash, sources of 27 

Purchasini?, general principles 39 

Purchase of fertilizer 32 

Roots 8 

Reversion of phosphates 24 

"Simples" 42 

Soil analysis, value of 61 

Soils, composition of 11 

Soils, fix phosphorus 24 

Soils, drainage of 16 

Soils, physical condition 15 

Source of fertilizers 19 

Solubility in different soils 30 

Stable manure 53 

Steamed bone 25 

Straw, fertilizing value 64 

Summer cover crop 56 

Thomas phosphate slag 25 

Unnecessary fertilizers, avoiding purchase 50 

Use of fertilizers . 47 

Vetch, common, fertilizing value 64 

Vetch, green manure 54 



AR 6 1912 



